Street Usage with Google Ridefinder

Via Mauro, a very nice map hack to visualize the paths of SuperShuttle buses in New York. Close to one of my possible future endeavor, collecting public transport usage data in Barcelona to create context aware applications.

I Started pulling down the XML for NYC every 5 minutes (the minimum update interval for ridefinder) and gathered about 1500 files over the past 5 days. Approximately 25-40 vehicles listed at any point, so at least 40,000 coordinates. The feed does not individually identify each vehicle, so it would be tricky to try and trace points together based on proximity and trajectory. And at five minute granularity, tracks would cross corners, connect over tunnels, etc.

The Impact on Collaboration of the Inherent Uncertainties of Positioning Technologies

Life on the Edge: Supporting Collaboration in Location-Based Experiences (CHI 2005, April 2005, Portland, USA), by Bendford (Mixed Reality Laboratory, University of Nottingham), Richard Hull (HP Lab in Bistol) and Jo Morrison (NESTA Futurelab) is an ethnological approach to an area I am very interesting in: the user’s experience of positioning technologies (or pervasive technologies in general) and more precisely the impact of their inherent uncertainties. I could find a lot of similarities between their experiment called Savannah and CatchBob! Themes I could bring back to CatchBob! are:

• How does the user interact with invisible sensing systems,
• How (un)awareness are the users of how they are being tracked (e.g. accuracy of the positioning),
• How do users address the difficulty of the system (e.g. when lost of connectivity or no position),
• How do users know and learn how to avoid and rectify the system’s mistakes (e.g. learning to detect the seams and cold spots),
• Do users detect uncertainty and what are the clues,
• How do users establish a shared context and coordinates their actions in moments of uncertainty.

In CatchBob! we thought of giving only rough positioning information or even inaccurate positions. My feeling is that in our game, users are more disturbed by the latency created by the communication system (some players even question if all the messages are being broadcasted) rather by the drift, jitter, lag and unavailability of the positioning system.

Some other pieces of information from this papers and about Savannah:

• Players halt when they encounter new information
• Players assume the the PDA is the sensing object, when in fact the sensor (GPS unit) is on their back
• System latency was also a factor in players’ difficulties; there could be a few seconds delay between a player’s PDA sending a position update, receiving new information from the game server and the player reacting and coming to a halt.
• There appears to be a considerable divergence between the player’s view off forming a group and the underlying system’s view, and this demonstrably can lead to serious confusion and frustration when players are unable to establish a shared context and act together.
• The system view of grouping is far more rigid. The system interprets multiple sources of data, which are often clouded by uncertainty and latency, and makes concrete and discrete decisions about when the groups have formed.
• When is it appropriate to work with absolute position and when relative?

Location-Based Applications at CRAFT

Nicolas and I wrote a 4-pages document that summarizes CRAFT’s research projects on Location-Based Services “lbs@craft“. It gives an overview of CatchBob!, Shoutspace and STAMPS. It also presents few results about CatchBob! as well as the issue we have to dealt with while designing those applications. It is not targeted to any special audience and will be used in the upcoming 2005 EPFL I&C Research Day.

In the last page, we talk about the various lessons we learning from the design of location-based services. I cover the current topics I am interested in pervasive technologies: Mixed approach to positioning, Indoor 3D positioning, Managing uncertainty, Latency, and engaging technology.

Dealing with Embarrassing Web Personality

With Google archiving web pages and even newsgroups, it is getting almost impossible to have power on old content or get rid off annoying homonyms. From Loosing Google’s Lock on the Past, experts say:

The most effective way to define and control your digital persona is to start a blog or put up a home page.

GridLock, a Collaborative Urban Board Game

GridLockd! is a large urban game where four teams compete to capture as many grid positions within a half hour on a city-based game board. This project is meant to display how semacodes, camera phones, ad-hoc groups, and social dynamics are effected under time pressure. Hopefully it is not yet another paperware, and we will soon see emerge real game images and study results.

Skyhook Wireless Gets Some Media Attention

Via Roland Piquepaille. Skyhook Wireless is yet another company doing WiFi positioning. Their business model comes from a well known practise in the locative media community. They provide a database of location of 802.11 access points. They claim it to be nationwide. Based on that they provide a few specific services (E911 location support, asset tracking, advertising according to the user’s context). The managed to get some attention in the press like the Boston Globe’s “One more way to find yourself”

Comparaison of position accuracy the GPS and Wi-Fi signals depending on the area where you are. (Credit: Skyhook Wireless)

Illustration showing how the client part of the Skyhook Wireless system works. (Credit: Skyhook Wireless)

Una Giornata a Milano

Tracking and Measuring Performance in Football

Sport Universal Process offers top football teams data and tools to analyze their games. Tracking the 22 players, the referee, and the ball is done with 8 cameras placed around the football field. The data generated (25 measures by second, 4.5 million positons) can be used in a replay tool that displays the fields from the top but also gives access to the footage from the cameras.

From that technology, they provide a way to broadcast live games on mobile devices.

My Presentation at Pompeu Fabra

I presented my work on locative media at the University of Pompeu Fabra in Barcelona. Here are the ppt slides.

3 dias en Barcelona